Feeder for abrasives



Sept. 26, 1933. J, SODERBERG 1,928,036

FEEDER FOR ABRASIVES Filed Nov. 26, 1932 2 Sheets-Sheet l gnuwwbo. z

Sept. 26, 1933.

J. SODERBERG FEEDER FOR ABRAS IVES 1932 2 Sheets-Sheet Filed Nov. 26

Patented Sept. 26, 1933 FEEDER Foa ABBASIVES Jacob Soderberg, Pittsburgh, Pa., assignor to i Pittsburgh Plate Glass Company, a corporation of Pennsylvania Application November 26,- 1932 Serial No. 644,413-

'5 Claims. (01. 51 -263) The invention relates to apparatus for feeding a mixture of abrasive (ordinary sand) and water to a grading apparatus, the particular use shown being the supply of the mixture to' a grading system where the abrasive is usedin grinding the edges of heavy glass plates, but the invention is of more general application and may be employed in any relation in which it is desired to feed abrasive and water from storage to a point of use. In a grading system for use in grinding plate glass, it is necessary to supply new coarse abrasive to the system as the material in use is gradually broken up and reduced in size, which calls for replenishment of-the coarser grades. It is desirable that this supplyshould be constant rather than intermittent as an intermittent or irregular supply of abrasive adversely affects the clogging and which is subject to an adjustment so i that exactly the right amount of abrasive is accurately supplied to meet any requirement. The

' desired result is accomplished by the use'of spe-- cial valve which is opened at predetermined intervals by a continuously operated motor so that the flow of abrasive mixture when it does occur is of relatively large volume, thus washing out any abrasive which may settle in the supply pipe and tend to cause clogging. One embodiment of the invention is illustrated in the accompanying drawings, wherein:

Figure l is a side elevation showing the general arrangement of the appparatus as applied to a glass grinding system employing a rub bed. Fig. 2 is a side elevation of the apparatus on a larger scale than that of Fig. 1. And Figs. 3, 4 and 5 are enlarged detail views, Fig. 3 being a plan View,

Fig. 4 a section on the line IV-IV of Fig. 3, and

Fig. a side elevation.

Referring to the drawings, 1 is a sand and water storage receptacle having a rubber conduit or hose 2 leading to the hopper 3 which in turn.

discharges to a sump 4 through the conduit 5. The mixture of sand and water in the sump is carried up into the grading tank 6 by the pump '7, and the finer sand, eliminated over the upper edge by the upflow of water through the tank.

The coarse sand which is required for the grinding operation is supplied through the pipe 8 to sand box 9 and thence discharges upon the-ro tating table or rub bed 10, the heavy'glass sheets whose edges are to be ground being supported in vertical position so that their lower edges engage the table, this beinga procedure well known in the art. The waste water and sand which flows from the table is caught in a gutter and con ducted through the pipe ll'to the sump. This used sand is again carried up into the grader'and the part thereof which is coarse enough to use, is again removed through the pipe 8, the remainder of the sand, which is too fine for use to advantage being removed over the top of the tank as heretofore pointed out. p

i The apparatus, to which the invention here particularly relates, comprises means for controlling the flow of abrasive and waterfrom the storage tank 1 through the conduit or hose 2 and will be understood by reference to Figs. 2 to 5. This apparatus includes a bracket 12 whichis bolted to the top of the hopper3 and has a flat plate 13 lying against one side of the rubber conduit 2. Ex-' tending longitudinally of the bracket isa shaft 14 mounted in suitable bearings on the bracket and are normally held yieldingly in thispositionxbymeans of a crank arm 1'7, keyed totheend of the shaft 14, and by the weight 18 carried on end 'of the crank arm.

The crank arm also carries ablock 19 mounted on stud bolts 20 so as to permitof -rockingmove-,

carrying a pair of arms 15, beween which is the ment, and through the block extends a connectting rod 21 which is screw threaded and carries a sleeves 22 which is freely slidable in the block. The lower end of the sleeve is seated in and secured to the knurled knob 23 which acts as a stop member, as later described. By rotating the knob, the sleeve may be adjusted up and down on the rod. It is locked in position bythe' thumb screw 24. The upper end of the rod "21 is pivoted. to a crank 25 and the crank is rotated to reciprocate the rod 16, which engages the conduit .2 and clamps it shut, to move backfrom such conduit, sothat by gravity a quantity ofthe abrasive mix ture is discharged t'o'the hopper 3 beneath. On the downward movement of the rod-21, the stop 23 moves down, permitting the weight 18 to move the leverarm downward, thus moving the rod 16 back to the position shown, at which time it clamps the conduit 2 against theplate 13 and closes it. By adjusting the position of the sleeve 22 longitudinally ofthe rod 21, the amount of opening of the conduit during the reciprocation of the rod' is regulated. This provides a very close adjustment of the abrasive supply, and permits the supply of as small a quantity of abrasive as may be needed without any danger of clogging to positively close the conduit without the application of such pressure as might cut or injure the hose. The apparatus will function indefinitely without attention and without any requirement for replacement or repair.

What I claim is:

, 1. Apparatus for supplying a mixture of abrasive and water from a storage receptacle to a grading system, compr sing a conduit of flexible material, means for yieldingly compressing the conduit to close it, a continuously operating motor and a lost motion connection between said means and the motor whereby said means is intermittently moved to position to permitthe conduit to open.

2; Apparatus for supplying a mixture of abrasive and water, from a storage receptacle to a grading system, comprising'a conduit of flexible material, a clamping member for compressing the conduit to 'close it, means normally applying yielding force to move the clamping member to a position closing the conduit, a continuously operating motor, aconnecting rod which is reciprocated back and forth-bythe motor, and a lost motion connection between the clamping means andthe connectingrod for movingthe clamping means to position permitting the conduit to open upon each reciprocation of the connecting rod. 7 I

3. Apparatus for supplying a mixture of abrasive and water from a storage receptacle to a grading system, comprising a conduit of flexible material, means for yieldingly compressing the conduit to close it, a continuously operating motor, a lost motion connection between said means and the I motor whereby said means is intermittently moved to position to permit the conduit to open, and means for adjusting the lost motion in said connection to regulate the degree of opening of the conduit by said connection. I

epApparatus for supplying a mixture of abrasive and water from a storage receptacle to a grading system, comprising a conduit of flexible material, a clamping member for compressing the conduit to close it, means normally applying yielding'force to move the clamping member to a position closing the conduit, a continuously operating motor, a connecting rod which is reciprocated back and forth bythe motor, a lost motion connection between the clamping meansand said rod for moving the clamping means to position permotor, a connecting rod whichis reciprocated back and forth by the motor, a crank connected to the clamping member; comprising an. arm through which the rod slides freely, and an adjustable stop on the rod on one side oi said arm adapted when therod moves in one direction to swing the said arm to cause the clamping means to move so as to permit the conduit to open. JACOB SODERBERG. 

